Delay arming device for fuses



Dw 1943- J.. F. M cAsLlN ET AL- 2,457,254

DELAY ARMING DEVICE FOR FUSES Filed Sept. 18, 1947 2 Sheets-Sheet 1 I I3 1- :Fj g.

grwc/wtms 1/ James M= cash-n BET'L Fink Dec. 28, 1948. J. F. M' CASLIN ET AL 2,457,254

DELAY ARMING DEVICE FOR -FU$ES Filed Sept. 18, 1947 2 Sheets-Sheet Z Patented Dec. 28, 1948 Fink, Defavaan, Wrsr; said assignor to The, George Bor C rp on, H a m Wi a corp at on; o D laware Application September 18, 194% Serial No. 774,752

The present invention relates to improvements in projectile fuzes, and more particularly to a delay arming device for such fuzes'.

An important object of the present invention is to provide adevice of: this character-which will delay-arming oi the fuze until the projectile hasreacheda point so far from the gun that detonation of the projectile will not endanger the gun crew.

Another object of the invention is the provi-- sion of a device of this character which will not be inadvertently armed by shocks or jars before firing of the projectile.

' A further object of the invention is the provision of a device of this character which will be positively maintained in its armed position once it has attained that position.

Still another object of the invention is to provide a device of this character'which is reliablein operation and which may be used with standardfuzes, boosters and projectiles.

Other objects and advantages of the invention will be apparent during the course of the followingdescription.

the accompanying drawings which form a part of this specification andwherein like charactors of reference denote like parts throughout,

Figure 1 is a top plan view of this invention showing the cover plates in position;

Figure 2 is a similar view with the cover platesrernoved showing the device in its initial safe, unarmed position; v

Figure 3 is a. view similar to Figure 2 showing the fully armed position of the device;

Figure 4 is a sectional view on the line 4-4 of- Figure 2, showing the escapement gear train in:

elevation; r I

Figure5 is. a sectional view on the line 5-5 of: Figure 3, parts being broken away;

Figure 6-. is a similar View on the line 66 of Figure: 2;,

Figure '71 is. a top plan view on. a smaller scale of the housing of the device with its movable parts removed and. with parts being shown in section;

Figure 8 is a detail. perspective View of" the arming; rotor; s

Figure!) is adetail. view showing thesafety wires.

in position, with parts shown in section andparts broken away; and

Figure 10 is a detail sectional view showing the rotor locking pin in. looking position.

In. the drawings; wherein. for the purpose of illustration is shown a preferred embodiment. of: the invention, the numeral 11' designates. a ho us-.

-: 1,. Claim. (01. Lois-19 shown) with the booster i2; the-fjuze, housing and booster being adapted to be carried by the forward, portion of a, rotatable type projectile in the i usual: manner. As. illustrated in Figures 4. and. 5,

the housing 1;]: is formed with. a substantially. solidrear portion t3 which is. recessed to form a. forwardly opening: relatively deep rotor well M. of. substantially circular shape and disposed; eccenmcally withinthe housing. A flash pas-t. sage: k5. extends axially through the solidvrear portion: 13 of the housing andopens into. the rotor well t4; ecoentrical-ly' of the center of the well; and connects the well: with the. booster IL: Arr escapement recess [.61 is shallower than well t4 and communicates therewith. 'Iwooppositely disposed recesses i1 and t8 are still shallower than escapement recess i5 and communicate with rotor well I41 The disposition of these re: cesses is best illustrated in Figure 7 in. which theinternal parts are removed to show the interior of the. housing.

A rotor- E9 is rotatably mounted within the well M upon a shaft 20' carried by the solid portion. of the housing which formsthe bottom. or rear wall of the recess. shown. in Figure- Z, theshaft Z6 isspaced from the. flash passage t5=but is dis-. posed centrally of well I4. The body of the rotor is. irregularly shaped and eccentri'cally disposed with. respect to. the; shaft 2! with. its. largest. and. heaviest portion 2i arranged on. one. side of. the. shaft and. the smallest,.. lightest portion 22. dis-.j posed on the opposite side of the shaft. Conse quently, when. thehousing is rotated rapidly,'therotor will be caused to rotate about; shaft 20 by the action of centrifugal force. The: smaller side 22 ofthe rotor is provided with aborespaced from shaft 20 and. containing. the detonator 23. When. the rotor is moved to" the armed position. shown in Figures 3 and 5, the detonator Z3; is. in. linewith. flash passage. L5 and when in its normal unarmed position the detonator is out of registration. with flash passage. I5= as iflslustratedtin Figure 6;.

The forwardportion of the rotor is. provided. with a gear plate 24 which may be formed in-= tegrally'with'. the rotor but is preferably formed separately and secured thereto in. any suitable: manner, as by meansof bolts or screws 25, The: gear plate fits into: a cutout portion of the for'e. ward face ofthe rotor and is flush with the uncut portion'of said. face of the rotor. The inner edge: at" the gear plate is curved to avoidyshatt 20 and; detonator 23,. as seen in Figures 2 and 3.. ,Ther largergside 2b of the rotor is milled. out immedie.

ately adjacent the gear plate 24 as best seen in Figure 8, to permit the rotor to move past the escapement gears without interference.

The edge of the gear plate 24 is provided with gear teeth 26 for a portion of its periphery. A notch 21 is arranged in the periphery of the gear plate adjacent teeth 26 and a second not-ch 28 is disposed in the periphery of the gear plate on the opposite side of the gear teeth 26.

The recess I! in the housing has a detent or pawl 29 freely pivoted on a pin 39 in the recess. A spring 3| is mounted on a post 32 arranged in the recess and the end of the spring resiliently urges the free end of the detent 29 about its pivot 39 towards the gear plate. In the normal unarmed position of the device shown in Figure 2, the detent engages in notch 21 in the gear plate periphery to prevent rotation of rotor I9. A second detent 33 is pivoted on pin 34 in recess l8 of the housing at a point opposite to the detent 29 and is urged by spring 35 on post36 towards gear plate 24 into notch 28. By reason of the two oppositely arranged detents 29 and 33 engaging in notches 21 and 28, it is impossible for the rotor to be released for rotation by a jar such as caused by dropping or a blow, because any force which tends to move one of the detents out of its notch against the tension of its spring will tend to urge the other detent into even closer engagement with its notch. It is therefore unnecessary to provide a locking mechanism for the detents.

An escapement mechanism, to retard rotation,

of the rotor I9, is disposed in housing recess I6 and includes an escapement wheel 31 carried by a shaft 38, and a pallet 39 carried by shaft 40. The pallet 39 is provided with spaced pawls M which alternately engage the teeth of the escapement wheel 3! for regulating the rotation thereof. A pinion 42 is carried by shaft 38 behind escapement wheel 31. Shaft 43 is rotatably.

disposed in recess I6 in spaced relation to shaft 38 and carries a gear 44 in mesh with pinion 42 and a pinion 45 disposed ahead of gear 44. A shaft 46 is also journaled in recess I6 in spaced relation to shafts 38 and 43 and carries a gear 41 in mesh with pinion 45 on shaft 43. A relatively large pinion 48 is carried by shaft 46 ahead of gear 41 and is adapted to mesh with the teeth 26 on the periphery of the gear plate 24. The

gears and pinions are rigidly secured to their respective shafts so as to turn therewith, and combine to form a gear train connecting rotor I9 to escapement wheel 31 and pallet 39. The rear ends of the shafts 40, 38, 43 and 46 are journaled in the rear walls of the recess I6, as illustrated in Figure 4.

A cover for the rotor and escapement mechanism comprises a large section 49 shaped to cover the recesses I6, I! and I8 and adapted to be held in place by screws 50 which enter threaded openings in the housing. Openings 52 are provided in the cover section 49 to receive the forward ends of shafts 38, 34, 32, 36, 40, 38, 43 and 46. A smaller cover sections 53 is of a shape complementary to cover section 49 and serves to cover the rotor and rotor well I4. Screws 54 secure the section 53 to the housing while an opening 55 in the cover section registers with the flash opening I5 as indicated in Figures 1 and 5. An opening 56 receives the forward end of rotor shaft 20. Sections 49 and 53 are provided with a mating protuberance and recess indicated generally at 51 in Figure 1 so that neither of the plates can be applied in an inverted position. The screw openings in the cover plate may also be counter- 4 sunk so that the forward side of the plate section can be identified.

The portion of the gear plate 24 furthest from the detonator 23 extends beyond the body of the rotor and carries a depending pin or lug 58 in spaced relation to the body of the rotor. An angular passage or bore 59 extends through the wall of the housing and communicates with recess I4. In the unarmed position of the rotor shown in Figure 2, the space between the rotor I9 and pin 58 is disposed in alignment with the passage 59 so that an arming wire may be passed through the passage 59 and between the pin 58 and rotor body I9 to prevent rotation of the rotor. A stop pin 60 is arranged in the rear wall of the recess I4 and is adapted to engage the rotor in its armed position shown in Figure 3, to prevent overrunning of the rotor. The pin 58 is sufficiently short to clear the stop pin 60 as the rotor rotates. f

. In operation the device will be applied to a projectile while the parts are in the unarmed position shown in Figure 2 in which the rotor is held in position by the detents 29 and 33 with the rotor teeth 26 in engagement with the pinion- 48. Before the projectile is fired, the arming wire is withdrawn from passage 59 and the rotor is heldby the detents only. When the projectile is fired from a weapon and rotated rapidly by the rifling in the weapon, the 1two detents 29 and 33 will be forced outwardly by centrifugal force, against the tension of the detent springs, until the detents clear the rotor notches and free the rotor for rotation. Due to the fact that one side of the rotor is considerably heavier than the other, as soon as the detents release the rotor it will be rotated by centrifugal force, but due to engagement of rotor teeth 26 with pinion 48 its rotation willbe controlled and delayed by the escapement gear train. The rotor will continue to rotate until it moves out of engagement with pinion 48and engages stop pin 60 at which time it is in the armed position illustrated in Figure 3. The delay action of the escapement is such that the fully armed position will not be reached until the projectile is a safe distance from the weapon sothat the gun crew will not be in danger of injury from a premature explosion of the projectile. When the rotor reaches the stop pin 60 the detonator 23 is in registration with the flash opening I5 which is in communication with the booster I2, and the detonator is in position to be detonated by the fuze onimpact. Due to the fact that impact might jar the rotor away from the stop pin and disarm the projectile before it is detonated, it is desirable to lock the rotor in its armed position. This is accomplished by the mechanism shown in Figure 10 in which the periphery of the large portion 2| of. the rotor I9 is provided'.with a-radial recess 6| in which a lock pin 62 is loosely arranged. When the rotor engagesstoppin 69, rotor recess 6| is in registration with a radial recess 63 in the side wall of the housing recess I4 so that the lock pin 62 is free to move outwardly into recess 63 under the action of centrifugal force. Due to the fact that recess 63 is of a depth substantially'less than the'length of lock pin 62, the inner end of the lock-pin willremain in rotor recess 6| so that it will serve to lock the rotor against rotation in either direction.

While thepreferred embodiment of theinvention has been shown and described, it is 'to be understood that various changes in the size, shape and arrangement .of parts may be resorted 5 to Without departing from the spirit of the invention or the scope of the subjoined claim.

We claim:

A delay arming device for rotatable projectiles comprising a housing adapted to be disposed between the fuze and booster of the projectile, said housing having a flash opening therein arranged in communication with the booster, a rotor rotatably mounted in said housing, said rotor being heavier on one side of its axis of rotation than on its other side, a detonator carried by the rotor at a point spaced from its axis and adapted in one position to be out of registration with the housing flash opening and in another position of the rotor to be in registration with the flash opening, an escapement mechanism operatively connected to said rotor to retard its rotational movement, centrifugally released means comprising substantially diametrically opposed spring urged detents engaging the rotor to lock the rotor in its unarmed position with the detonator out of registration with the housing flash opening, and centrifugally actuated positive locking means to lock the rotor in its armed position with its detonator in registration with the housing flash 25 6 rotor body and having gear teeth adapted to engage said escapement mechanism, said gear plate having peripheral notches adapted to be engaged by the detents, said gear plate extending beyond one side of the rotor body and carrying a lug disposed in spaced relation to said side of the rotor body, whereby an arming wire carried by the housing may be passed between the lug and rotor body to lock the rotor in its unarmed position.

JAMES F. McCASLIN.

JEAN FINK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Brayton Nov. 17, 1925 Junghans Apr. 10, 1928 FOREIGN PATENTS Country Date Germany Oct. 26, 1905 Great Britain Feb. 16, 1928 Number Number 

